One of the problems that occur with an electrical fault in a body of water is that the current leakage into the body of water from the electrical fault can injure or kill a person through electrocution, which is often referred to as electric shock drowning. This invention relates generally to shock detectors and, more specifically, to shock detectors that can be used to prevent electric shock drowning by detecting the presence of an electric field and alerting a person that the body of water comprises a hazard to a swimmer or a person coming into contact with the body of water. Typically, the current leakage occurs from a faulty electrical connection on a boat or dock although other sources may create a hazardous water condition.
It is known that if a swimmer encounters a body of water with an electric field the swimmer can be electrocuted with a voltage gradient of as little as two volts per foot. The mere presence of the swimmer in the electric field causes the current flowing in the water to take a path of least electrical resistance through the swimmers body since the wet skin on a swimmer's body has a lower electrical resistance than the water surrounding the swimmer. If the voltage gradient is sufficiently high the current flowing through the swimmer's body can electrocute the swimmer. In still other cases a person may be electrocuted if he or she comes into incidental contact with a body of water, which has leakage from an electrical source.
In addition to the existence of a harmful voltage gradient in a body of water there is a need to safely locate the source of the harmful voltage gradient as well as to ensure those proximate the body of water that the water does or does not contain a hazardous electrical field.
Another problem with harmful electrical conditions in a body of water, such as harmful voltage or harmful current conditions that may injure or kill a person, is that the harmful electrical conditions may be localized in the body of water so that one portion of the body of water contains a harmful electrical condition while another portion of the same body of water does not contain the harmful electrical condition. That is, the harmful electrical condition is dependent on various conditions including any underwater structures. Consequently, the existence and the shape of field of the harmful electrical condition proximate a shock detector may be beyond the visual alarm range or the audible alarm range of the shock detector. Thus, one may find that in one location in the body of water a shock detector indicates the presence of a harmful electrical condition and in another location in the same body of water a further shock detector, which may be out of sight of the first shock detector, does not indicate a harmful electrical condition. As a result one may not be alerted to a nearby presence of the harmful electrical condition until one is within the field of the harmful electrical condition.